The Laboratory Of Microbial Ecology of the Rhizosphere and extreme Environments (LEMiRE) is part of the UMR 6191 “CNRS-CEA-Université Aix-Marseille II” and part of the FR ECCOREV.
The main objectives of LEMiRE are to determine the molecular dialogue between plant and bacteria in the rhizosphere by using an integrative approach which takes into account the plant physiology, the dynamics of carbon released by roots into soil, its use and transformation by soil bacteria into exopolymers and other secondary metabolites, their role on plant health and plant-bacteria signalling and communication.
The equilibrium of this integrative system is investigated under natural conditions and also in the presence of pollutants such as heavy metals or nanoparticles. This study is devoted to gain knowledge on metal toxicity on sensitive and tolerant soil bacteria by using functional genomics.
More recently a novel topic has emerged, concerning bacterial adaptation to extreme environments (UV or gamma radiation, desiccation, heavy metals), by using metagenome approach to get access to the inaccessible genes belonging to non-culturable bacteria, and also by isolating bacteria from extreme environment. Among these bacteria, a new species isolated from Sahara showed a higher tolerance to gamma and UV radiation than Deinococcus radiotolerans. The mechanism of radio-tolerance of this new species is under investigation, and we aim to develop and reinforce this new topic in the future.
To deserve these themes, a great effort has been devoted to set up tools and methodologies for bacterial genotyping, taxonomy, new isotopic approaches such as DNA-SIP, gene profiling by using DNA microarrays, and development of bio-informatics tools for new sequenced genomes annotation.